﻿using System.Security.Cryptography;
using System.Text;

namespace Yi.AspNetCore.Helpers;

public class MD5Helper
{
    /// <summary>
    ///     生成PasswordSalt
    /// </summary>
    /// <returns>返回string</returns>
    public static string GenerateSalt()
    {
        var buf = new byte[16];
#pragma warning disable SYSLIB0023 // 类型或成员已过时
        new RNGCryptoServiceProvider().GetBytes(buf);
#pragma warning restore SYSLIB0023 // 类型或成员已过时
        return Convert.ToBase64String(buf);
    }

    /// <summary>
    ///     加密密码
    /// </summary>
    /// <param name="pass">密码</param>
    /// <param name="passwordFormat">加密类型</param>
    /// <param name="salt">PasswordSalt</param>
    /// <returns>加密后的密码</returns>
    public static string SHA2Encode(string pass, string salt, int passwordFormat = 1)
    {
        if (passwordFormat == 0) // MembershipPasswordFormat.Clear
            return pass;

        var bIn = Encoding.Unicode.GetBytes(pass);
        var bSalt = Convert.FromBase64String(salt);
        var bAll = new byte[bSalt.Length + bIn.Length];
        byte[]? bRet = null;

        Buffer.BlockCopy(bSalt, 0, bAll, 0, bSalt.Length);
        Buffer.BlockCopy(bIn, 0, bAll, bSalt.Length, bIn.Length);

#pragma warning disable SYSLIB0021 // 类型或成员已过时
        var s = SHA512.Create();
#pragma warning restore SYSLIB0021 // 类型或成员已过时
        bRet = s.ComputeHash(bAll);

        return ConvertEx.ToUrlBase64String(bRet);
    }

    /// <summary>
    ///     16位MD5加密
    /// </summary>
    /// <param name="password"></param>
    /// <returns></returns>
    public static string MD5Encrypt16(string password)
    {
        var md5 = MD5.Create();
        var t2 = BitConverter.ToString(md5.ComputeHash(Encoding.Default.GetBytes(password)), 4, 8);
        t2 = t2.Replace("-", string.Empty);
        return t2;
    }

    /// <summary>
    ///     32位MD5加密
    /// </summary>
    /// <param name="password"></param>
    /// <returns></returns>
    public static string MD5Encrypt32(string password = "")
    {
        var pwd = string.Empty;
        try
        {
            if (!string.IsNullOrEmpty(password) && !string.IsNullOrWhiteSpace(password))
            {
                var md5 = MD5.Create(); //实例化一个md5对像
                // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择　
                var s = md5.ComputeHash(Encoding.UTF8.GetBytes(password));
                // 通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得
                foreach (var item in s)
                    // 将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符 
                    pwd = string.Concat(pwd, item.ToString("X2"));
            }
        }
        catch
        {
            throw new Exception($"错误的 password 字符串:【{password}】");
        }

        return pwd;
    }

    /// <summary>
    ///     64位MD5加密
    /// </summary>
    /// <param name="password"></param>
    /// <returns></returns>
    public static string MD5Encrypt64(string password)
    {
        // 实例化一个md5对像
        // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择　
        var md5 = MD5.Create();
        var s = md5.ComputeHash(Encoding.UTF8.GetBytes(password));
        return Convert.ToBase64String(s);
    }
}

public class ConvertEx
{
    private static readonly char[] padding = { '=' };

    public static string ToUrlBase64String(byte[] inArray)
    {
        var str = Convert.ToBase64String(inArray);
        str = str.TrimEnd(padding).Replace('+', '-').Replace('/', '_');

        return str;
    }

    public static byte[] FromUrlBase64String(string s)
    {
        var incoming = s.Replace('_', '/').Replace('-', '+');
        switch (s.Length % 4)
        {
            case 2:
                incoming += "==";
                break;
            case 3:
                incoming += "=";
                break;
        }

        var bytes = Convert.FromBase64String(incoming);

        return bytes;
    }
}